Unauthenticated service hang via malformed VBA decompression
Published Mar 4, 2026 · Updated Mar 4, 2026
Denial of service in Cisco products using Snort 3 VBA decompression allows remote attackers to hang the Detection Engine with crafted VBA data. Improper error checking in the Snort 3 VBA decompressor fails to terminate processing after malformed decompression data, leaving the engine in an infinite loop. Snort 3 and VBA decompression must be active; VBA decompression is disabled by default, and successful exploitation interrupts Snort traffic inspection.
Summary
What happened
Denial of service in Cisco products using Snort 3 VBA decompression allows remote attackers to hang the Detection Engine with crafted VBA data. Improper error checking in the Snort 3 VBA decompressor fails to terminate processing after malformed decompression data, leaving the engine in an infinite loop. Snort 3 and VBA decompression must be active; VBA decompression is disabled by default, and successful exploitation interrupts Snort traffic inspection.
The record
- CVE
- CVE-2026-20054
- Published
- Mar 4, 2026
- Updated
- Mar 4, 2026
- Vendor
- ClamAV
- Product
- Cisco Cyber Vision
- Classifications
- CWE-835, T1499.004
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Mar 4, 2026CVE publishedPublication date reported by the CVE source.
- Mar 4, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=3.0.0
- Affected versionversion=3.0.1
- Affected versionversion=3.0.2
- Affected versionversion=3.0.3
- Affected versionversion=3.0.4
- Affected versionversion=3.0.5
- Affected versionversion=3.0.6
- Affected versionversion=3.1.0
- Affected versionversion=3.1.1
- Affected versionversion=3.1.2
- Affected versionversion=3.2.0
- Affected versionversion=3.2.1
- Affected versionversion=3.2.2
- Affected versionversion=3.2.3
- Affected versionversion=3.2.4
- Affected versionversion=4.0.0
- Affected versionversion=4.0.1
- Affected versionversion=4.0.2
- Affected versionversion=4.0.3
- Affected versionversion=4.1.0
- Affected versionversion=4.1.1
- Affected versionversion=4.1.2
- Affected versionversion=4.1.3
- Affected versionversion=4.1.4
- Affected versionversion=4.1.5
- Affected versionversion=4.1.6
- Affected versionversion=4.1.7
- Affected versionversion=4.2.0
- Affected versionversion=4.2.1
- Affected versionversion=4.2.2
- Affected versionversion=4.2.3
- Affected versionversion=4.2.4
- Affected versionversion=4.2.6
- Affected versionversion=4.2.X
- Affected versionversion=4.3.0
- Affected versionversion=4.3.1
- Affected versionversion=4.3.2
- Affected versionversion=4.3.3
- Affected versionversion=4.4.0
- Affected versionversion=4.4.1
- Affected versionversion=4.4.2
- Affected versionversion=4.4.3
- Affected versionversion=5.0.0
- Affected versionversion=5.0.1
- Affected versionversion=5.0.2
- Affected versionversion=5.1.0
- Affected versionversion=5.1.1
- Affected versionversion=5.1.2
- Affected versionversion=5.1.3
- Affected versionversion=5.2.0
- Affected versionversion=5.2.1
- Affected versionversion=5.3.0
- Affected versionversion=5.3.1
- Affected versionversion=5.3.2
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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